Linux 6.6 Will Make It Easy To Disable IO_uring System-Wide

Written by Michael Larabel in Linux Storage on 14 July 2023 at 11:23 AM EDT. 31 Comments
While IO_uring has been one of the most interesting kernel innovations of recent years and can allow for great speed-ups to async I/O, there have been some security concerns and with the Linux 6.6 kernel it will be easier for Linux administrators to disable it system-wide if so desired.

IO_uring has yielded some security concerns and vulnerabilities particularly for those sticking to older versions of the Linux kernel. There has also been IO_uring integration issues with the Linux security subsystem. Most notable was Google last month Google noting how IO_uring has yielded ~60% of the submissions to Google's Vulnerability Rewards Program. Google has paid out around one million dollars worth of rewards around IO_uring vulnerabilities. This has led Google to restrict or even block IO_uring access on their servers, Android, and Chrome OS platforms.

Submitted by Google engineer Matteo Rizzo, the upstream Linux 6.6 kernel is set to add a new sysctl interface for disabling IO_uring system-wide. The io_uring_disabled sysctl knob is being added that if set to a value of one will block all processes from calling IO_uring's setup function except for those privileged users with the system administrator capability (CAP_SYS_ADMIN). Or if io_uring_disabled is set to a value of 2, it will block all processes regardless of privilege level.

By default all processes will still be able to create IO_uring instances but for those wanting to limit or completely disable IO_uring access will now have this easy sysctl tunable rather than restoring to building your own kernel or similar modifications.

io_uring_disabled sysctl

The patch was picked up this week by linux-block's for-next branch as part of the for-6.6/io_uring material making it part of the changes to be sent in at the end of summer for the Linux 6.6 cycle.
Related News
About The Author
Michael Larabel

Michael Larabel is the principal author of and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via

Popular News This Week